Posts

Showing posts from July, 2013

CT scanning in kids and radiation exposure

The use of CT scans is increasing dramatically in kids. data collected from 7 large HMOs in the US over 10 years (2001-2011) in kids <15yo, with 4.9M child-years of observation (see  radiation exposure and cancer. jama peds 2013 in dropbox).  one advance in this study is that they collected the actual technical parameters (radiation dose) used in diverse facilities.   major findings: -- a doubling of CT scans done in kids <5yo over this 10-year spread (from 11 to 20 scans/1000 kids) and tripling in those 5-15 (from 10.5 to 25/1000 kids) -- with numbers leveling off or slightly decreasing in the later years. --large variability of radiation dose per scan at different sites. highest dosages overall with abd/pelvic CTs   (40% done for pain, 11% for r/o appendicitis, 6% for infection) --Head CT was the most commonly done CT and increased 50%, though the % increase was highest in abd CT  for children 5-14yo.  --using risk models (some based on the Japanese atomic bomb sur

glycemic index

as i've mentioned in several prior emails, there are pretty impressive data on the positive effects of a low glycemic index (GI) diet (ie one which documents the actual effect of different foods on the actual blood glucose levels). in general, high glycemic foods are associated with higher blood sugar levels and higher insulin levels in the early postprandial period, subsequently followed by low blood sugar levels (below the basal preprandial level), and associated increased hunger, food intake, and possibly weight.  also, high glycemic meals are associated with high triglycerides and lower HDL levels.  for an old but useful article, see  glycemic index ludwig jama 2002  in dropbox (or JAMA 2002; 287:2414-2423) for a more detailed physiologic description.   subsequent data have consistently found that low glycemic diets improve cholesterol/HDL ratios and are at least as good as low fat diets in decreasing weight (interestingly, several studies have shown that an ad lib low glycem